Oilfield oil well fishing tools H type safety joint
Type H Safety Joint, which is installed on the position required for subsurface drill stem and can bear in fishing operation all kinds of loads for pulling or pressing and used to transmit torque, is a subsurface safety equipment. In down hole operation, in case of being needed, the safety joint is easy to be discharged off so as to take out the drill stem above it. It is easy to butt the safety joint to go on fishing operation when running in hole again.
In drill strings, the safety joint should be located above the drill collars to avoid compression.
In fishing strings, the safety joint should be located directly above the fishing tool but below the jar or bumper sub.
In wash over strings, the safety joint should be located between the drill pipe and the wash over pipe. Wash over Safety Joints are provided with a tool joint box thread and a wash over pipe pin thread.